Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net deferred gains (losses) on derivatives-hedging activities, tax	$ (74)	$ (20)	$ 161
Changes in unrealized net gains (losses) on investment securities, tax	23	(59)	(136)
Changes in net unrecognized pension and other postretirement benefit costs, tax	29	189	(341)
Net derivative (gains) losses-hedging activities, tax	68	(59)	(53)
Net realized (gains) losses on investment securities, tax	29	33	35
Net pension and other postretirement benefit costs, tax	(35)	(24)	(39)
Changes in other comprehensive income (loss) from equity method investees, tax	1	3	0
Virginia Electric and Power Company
Net deferred gains (losses) on derivatives-hedging activities, tax	2	2	(3)
Changes in unrealized net gains (losses) on investment securities, tax	1	(9)	(13)
Net derivative (gains) losses-hedging activities, tax	0	2	0
Net realized (gains) losses on investment securities, tax	4	4	2
Dominion Gas Holdings, LLC
Net deferred gains (losses) on derivatives-hedging activities, tax	(4)	19	(27)
Changes in net unrecognized pension and other postretirement benefit costs, tax	13	6	(18)
Net derivative (gains) losses-hedging activities, tax	3	(5)	(5)
Net pension and other postretirement benefit costs, tax	$ (3)	$ (3)	$ (4)